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前言

        本文介绍Linux系统下自带的文件IO的函数。

Linux文件IO相关函数

open函数

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int open(const char *pathname, int flags);
int open(const char *pathname, int flags, mode_t mode);

close函数

#include <unistd.h>
int close(int fd);

read函数

#include <unistd.h>
ssize_t read(int fd, void *buf, size_t count);

write函数

#include <unistd.h>
ssize_t write(int fd, const void *buf, size_t count);

lseek函数

#include <sys/types.h>
#include <unistd.h>
off_t lseek(int fd, off_t offset, int whence);

三个文件描述符

        标准输入：0
        标准输出：1
        标准错误：2

目录操作函数

stat函数

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
int stat(const char *pathname, struct stat *statbuf);struct stat {dev_t     st_dev;         /* ID of device containing file */ino_t     st_ino;         /* Inode number */mode_t    st_mode;        /* File type and mode */nlink_t   st_nlink;       /* Number of hard links */uid_t     st_uid;         /* User ID of owner */gid_t     st_gid;         /* Group ID of owner */dev_t     st_rdev;        /* Device ID (if special file) */off_t     st_size;        /* Total size, in bytes */blksize_t st_blksize;     /* Block size for filesystem I/O */blkcnt_t  st_blocks;      /* Number of 512B blocks allocated *//* Since Linux 2.6, the kernel supports nanosecondprecision for the following timestamp fields.For the details before Linux 2.6, see NOTES. */struct timespec st_atim;  /* Time of last access */struct timespec st_mtim;  /* Time of last modification */struct timespec st_ctim;  /* Time of last status change */#define st_atime st_atim.tv_sec      /* Backward compatibility */
#define st_mtime st_mtim.tv_sec
#define st_ctime st_ctim.tv_sec
};

opendir函数

#include <sys/types.h>
#include <dirent.h>
DIR *opendir(const char *name);

readdir函数

#include <dirent.h>
struct dirent *readdir(DIR *dirp);

closedir函数

#include <sys/types.h>
#include <dirent.h>
int closedir(DIR *dirp);